完成句子.
问题描述：
完成句子.
I'm so sorry______at such an awkward time,but I really had something urgent to tell you.(call)
我真的很抱歉在这么不合适的时间给你打电话,但我真的有急事告诉你.
have called you,请问为什么要用have done,不能只用do吗
How can you ask again?I think_____at all when I presented the answer to you.(listen)
你怎能再问一遍?我认为当时我在讲解答案时你根本没听.
答案是you were not listening,请问为什么不用情态动词表推测?
答
第一题：
have done 表明已经发生.怎么看得出来呢?因为后面的句子有过去时had.
如果是一般现在时,就能用to do,即 I'm sorry to call you at such ...,but I really have something ...
第二题：
用过去进行时,表示和“我讲解”同时发生.
用情态动词表推测也可以,即 You couldn't be listening at all when I presented the .此时,I think 不必用.